THERESA May's legacy will be "a cruel and callous hostile environment" over child trafficking, according to the SNP's Kirsty Blackman.

The party's deputy Westminster leader called on the PM to apologise for refusing hundreds of child trafficking victims the right to stay in the UK, as revealed by BuzzFeed News.

The investigation revealed only 16 out of 326 victims had their applications to stay in the UK approved in the 20 months to December 2018.

"Will she apologise or hang her head in shame?" Blackman asks.

May says "we do constantly look at how we can improve our response to modern slavery".

As one of her last acts as prime minister, Theresa May is promising money to help end modern slavery, something she has described as the "great human rights issue of our time".

It became a focus of hers during her time as home secretary, as she sought to highlight the more than 10,000 people in the UK estimated to be living in domestic servitude, labour exploitation or having been trafficked for sex.

Others have put the figure much higher.

The Modern Slavery Act 2015, introduced by May before she became prime minister, brought together existing offences into one law. It also created new duties and powers to protect victims and prosecute offenders.

It introduced a new defence for victims of slavery and trafficking who have been forced to break the law.